What should the top 10 clubs do in this summer's transfer window?

Remember the January transfer window? Neither do I.

The biggest transfer was 18-year-old Vitor Roque's €40-million move to Barcelona. He played 300-something minutes and scored two goals -- as a center forward. The only other moves involving fees of at least €25 million: full-back Sacha Boey to Bayern Munich and center-back Radu Dragusin to Tottenham. They combined for just over 500 total minutes for their new clubs.

The most impactful move ended up being then-19-year-old Adam Wharton's €21-million switch from Blackburn Rovers to Crystal Palace. He played at least an hour in every Palace game after he joined the club. They rose up the table, and he made the England squad for the Euros.

In short: things were quiet. Quieter than ever, maybe -- certainly quieter than last summer, when 85 different players moved for at least €25 million.

However, the lack of spending in January should mean that the money hoses are about to get cranked up as the temperature rises this summer. The growing impact of the financial controls implemented by various domestic leagues might mean certain clubs can't spend as much as they normally would, but it also might mean that certain clubs -- [takes out binoculars, sets sights on Chelsea's Stamford Bridge] -- have to transfer out players they otherwise wouldn't want to.

Throw in the Euros and the Copa America -- two international tournaments that typically inspire already irrational actors into making even more irrational decisions than usual -- and we should see a good deal of player movement this summer. Buckle up for a blockbuster transfer window.

So, with the Premier League transfer window opening on Friday, let's take a look at the 10 richest clubs in the world, per Deloitte's latest numbers, and see how their biggest needs stack up against each other. Some of these teams have very specific needs (see: Liverpool, Manchester City and Barcelona) while others have a lot of space to improve (hello, Manchester United), so let's dig in.